If it takes faucet A to fill the tank in 2 hours and faucet B takes 5 hours how long will it take if they work together?
2007-08-01 10:43:02 · 3 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
A = 1/2 tank filled per hour
B = 1/5 tank filled per hour
Together: 1/2 + 1/5 = 7/10 tank filled per hour
One tank filled at 7/10 tanks filled per hour =
1/(7/10) =
10/7 hours.
2007-08-01 10:47:05 · answer #1 · answered by McFate 7 · 1⤊ 0⤋
Use rates
Faucet fills 1/2 tanks per hour
Faucet B fills 1/5 tanks per hour
Add them together to get the total rate:
1/2 + 1/5 = 5/10 + 2/10 = 7/10
They fill a total of 7/10 of a tank per hour.
To fill one tank, do 1 / (7/10)
=(1/1) * (10/7)
= 10/7 hours
or 1.43 hours
2007-08-01 17:55:00 · answer #2 · answered by KevinT998877 2 · 0⤊ 0⤋
x/2 + x/5 = 1
(5x + 2x) = 10
5x = 10
x = 2 hours
2007-08-01 17:50:55 · answer #3 · answered by CPUcate 6 · 0⤊ 1⤋